dip_class_plot {bp}

Plot of Dipping Classifications

Description

Graphical visualization of the dip_calc output for categories of dipping percentages.

NOTE: Any reference to "sleep" in the bp package refers to an individual's nocturnal period; "sleep" is used in an informal sense for intuitive purposes. Technically, from a clinical perspective, indication of sleep is currently obtained through means of EEG or other highly specialized equipment. For all intents and purposes, sleep in the context of this package refers to actigraphy-inferred nocturnal periods of rest.

Usage

dip_class_plot(
  data,
  subj = NULL,
  dip_thresh = 0.1,
  extreme_thresh = 0.2,
  thresh_mult = 2,
  sleep_start_end = NULL
)

Arguments

data

User-supplied data set that must contain SBP, DBP, and either DATE_TIME or WAKE columns in order to distinguish between sleep and awake

In the event of non-ABPM data (i.e. a data set without a corresponding WAKE column), then a DATE_TIME column must be present in order to denote which times correspond to sleep and which times correspond to awake.

subj

Optional argument. Allows the user to specify and subset specific subjects from the ID column of the supplied data set. The subj argument can be a single value or a vector of elements. The input type should be character, but the function will comply with integers so long as they are all present in the ID column of the data.

dip_thresh

Default threshold for normal "Dipping" set to 0.10 (i.e. 10%). This value represents the maximum percentage that BP can fall during sleep and be characterized as "Normal" nocturnal decline (dipping). Specifically, this category includes all dips between 0% and this value.

extreme_thresh

Default threshold for "Extreme Dipping" set to 0.20 (i.e. 20%). This value represents the maximum percentage that BP can fall during sleep and be characterized as "Extreme" nocturnal decline (dipping). Specifically, this category includes all dips between the Normal dipping threshold and this value.

NOTE: dip_thresh cannot exceed extreme_thresh.

thresh_mult

Optional argument that serves as a multiplier by which to expand plot sizing for X and Y axis. Default set to 2.

sleep_start_end

Optional User-supplied manual override to adjust sleep interval indicating indicate start and end time corresponding to the sleep interval of interest. Must only contain 2 values and must be 24-hour denoted integers

Example: sleep_start_end = c(22,5) indicates a sleep period from 10pm - 5am.

Value

A scatter plot of all dipping percentage values layered on top of the category plot outlined in Okhubo et al. (1995). dip_thresh and extreme_thresh denote the cutoffs for the Normal and Extreme dipping categories. Any dips below zero are denoted as Inverted (or Reverse) dipping.

The default plot categories are as follows:

• INV: Inverted (Reverse) Dipper - no nocturnal decline (greater or equal to 0%)

• ND: Non-Dipper - a nocturnal decline between 0 - 10%

• DIP: Dipper - a nocturnal decline between 10% and the extreme dipping % (20%)

• ED: Extreme Dipper - a nocturnal decline exceeding 20%

References

Okhubo, T., Imai, Y., Tsuji, K., Nagai, K., Watanabe, N., Minami, J., Kato, J., Kikuchi, N., Nishiyama, A., Aihara, A., Sekino, M., Satoh, H., and Hisamichi, S. (1997). Relation Between Nocturnal Decline in Blood Pressure and Mortality: The Ohasama Study, American Journal of Hypertension 10(11), 1201–1207, doi: 10.1016/S0895-7061(97)00274-4.

Examples

hypnos_proc <- process_data(bp::bp_hypnos,
                               sbp = "syst",
                               dbp = "DIAST",
                               date_time = "date.time",
                               id = "id",
                               wake = "wake",
                               visit = "visit")

dip_class_plot(hypnos_proc)